package chat;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
 
 
public class ServerSocket {
	    private int port = 6001;
	    //解码buffer
	   // private CharsetDecoder decode = Charset.forName("UTF-8").newDecoder();
	    /*发送数据缓冲区*/
	    private ByteBuffer sBuffer = ByteBuffer.allocate(1024);
	    /*接受数据缓冲区*/
	    private ByteBuffer rBuffer = ByteBuffer.allocate(1024);
	    /*映射客户端channel */
		private String sendText;
	    private Map<String, SocketChannel> clientsMap = new HashMap<String, SocketChannel>();
		private Charset charset = Charset.forName("UTF-8");
	    private Selector selector;
	    private SimpleDateFormat sdf = new SimpleDateFormat("YYYY-MM-dd HH:mm:ss", java.util.Locale.US);
		int i=0;
	    public ServerSocket(){
	        try {
	            init();
	            listen();
 
	        } catch (Exception e) {
	            e.printStackTrace();
	        }
	    }
	    private void init() throws Exception{
	        /* 
	         *启动服务器端，配置为非阻塞，绑定端口，注册accept事件 
	         *ACCEPT事件：当服务端收到客户端连接请求时，触发该事件 
	         */  
	        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();  
	        serverSocketChannel.configureBlocking(false);  
	        java.net.ServerSocket serverSocket = serverSocketChannel.socket();  
	        serverSocket.bind(new InetSocketAddress(port));  
	        selector = Selector.open();  
	        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);  
	        System.out.println("server start on port:"+port);  
	    }
 
	    /** 
	     * 服务器端轮询监听，select方法会一直阻塞直到有相关事件发生或超时 
	     */  
	    private void listen(){
 
	        while (true) {
	            try {
	                selector.select();//返回值为本次触发的事件数  
	                Set<SelectionKey> selectionKeys = selector.selectedKeys();  
	                for(SelectionKey key : selectionKeys){
	                    handle(key);
	                }
	                selectionKeys.clear();//清除处理过的事件 
	            } catch (Exception e) {
	                e.printStackTrace();  
	                break;  
	            }  
	        }
	    }
 
	    /**
	     * 处理不同的事件 
	     */ 
	    private void handle(SelectionKey selectionKey) throws IOException { 
 
	        ServerSocketChannel server = null;
	        SocketChannel client = null;
	        String receiveText=null;
	        int count=0;
	        if (selectionKey.isAcceptable()) {
	            /* 
	             * 客户端请求连接事件 
	             * serversocket为该客户端建立socket连接，将此socket注册READ事件，监听客户端输入 
	             * READ事件：当客户端发来数据，并已被服务器控制线程正确读取时，触发该事件 
	             */  
	            server = (ServerSocketChannel) selectionKey.channel();
	            client = server.accept();
	            client.configureBlocking(false);
	            clientsMap.put(client.getLocalAddress().toString().substring(1)+ i++,client);
	            client.register(selector, SelectionKey.OP_READ);
	        } else if (selectionKey.isReadable()) {
	            /*
	             * READ事件，收到客户端发送数据，读取数据后继续注册监听客户端 
	             */
	            client = (SocketChannel) selectionKey.channel();
	            rBuffer.clear();
	            count = client.read(rBuffer);
	            if (count > 0) {
	                rBuffer.flip();
	                receiveText = charset.decode(rBuffer.asReadOnlyBuffer()).toString();
	                System.out.println(client.getLocalAddress().toString().substring(1)+":"+receiveText);
	                sBuffer.clear();
	                sBuffer.put((sdf.format(new Date())+"服务器收到你的消息").getBytes("UTF-8"));
	                sBuffer.flip();
	                client.write(sBuffer);
					new Thread(){
						@Override
						public void run() {
							while(true){
								try {
									//String name = "["+client.getInetAddress().toString().substring(1)+"]";
									InputStreamReader input = new InputStreamReader(System.in);
									BufferedReader br = new BufferedReader(input);
									sendText = br.readLine();
 
									if(!clientsMap.isEmpty()){
										for(Map.Entry<String, SocketChannel> entry : clientsMap.entrySet()){
											SocketChannel temp = entry.getValue();
											String name=entry.getKey();
 
											sBuffer.clear();
											sBuffer.put((name+":"+sendText).getBytes("UTF-8"));
											sBuffer.flip();
											//输出到通道
											temp.write(sBuffer);
										}
									}
								} catch (IOException e) {
									e.printStackTrace();
									break;
								}
							}
						}
					}.start();
 
					client = (SocketChannel) selectionKey.channel();
	                client.register(selector, SelectionKey.OP_READ);
	            }  
	        }
 
 
	    }  
	    public static void main(String[] args) throws IOException {
	    	new ServerSocket();  
	    }  
}